This recipe is for 2 quarts drinkable yogurt or 1 quart thick yogurt + 1 quart whey.
What I used:
- 1 - medium sized cooler
- 5 - 1/2 gallon mason jars
- 1/2 gallon fresh milk
- 1/2 cup store bought plain organic yogurt (I used "Nancy's Organic Whole Milk Yogurt")
- Simple Thermometer
- Kitchen Thermometer (such as the kind you use for roasts)
- Hot tap water
Step One: Fill all 5 mason jars with hottest tap water possible,seal and place 4 of them in cooler with simple thermometer to regulate temperature. Leave 5th one on the counter to warm remain warm. While cooler is warming up inside....
Step Two: SLOWLY warm 1/2 gallon of milk on stove top until it reaches about 105 degrees, being careful not to go above 110 degrees. *going over 110 compromises natural enzymes found in fresh milk - read more about all of that fun stuff HERE: http://nourishedkitchen.com/raw-milk-yogurt/
Step Three: Empty jar that was warming, pour most of warmed milk in pre-warmed jar, and using the last bit of milk to thin 1/2 cup store bought yogurt and pour that in with warmed milk. Put on a tight lid and give it a shake.
Step Four: Check cooler temp (should have warmed up in there to about 110 degrees), if it's too hot, remove a jar of water and leave the lid open for about 30 seconds. Close it up again, check the temp again in 5 minutes. You want it to be about 110 degrees (give or take a few). Add warmed jar of milk and yogurt mixture, close it up and DON'T OPEN IT AGAIN for at least 8 hours.
*if your cooler is not hot enough, maybe boil some water to fill one of the jars, add it to cooler, close and check temperature after 5 minutes.
Step Five: 8 hours later, open yogurt, give it a stir :) It should be about the thickness of a drinkable yogurt (or store bought kefir) - I haven't cultured it longer yet, but that might thicken it a bit more (above link recommends 8-12 hours).
FOR A THICKER YOGURT:
Place colander over a bowl, line it with a very thin kitchen towel or cheesecloth (I use what's called "flour sack towels").
Pour your yogurt into colander and let it strain in the fridge for a a few hours or overnight (I cover the top with plastic wrap). The longer you let it drain, the thicker a yogurt you will get. If you let it drip long enough you will get cream cheese :D which is tasty. Overnight will yeild a nice thick yogurt like pictured above. The liquid (whey) that drips out is highly useful in making other things - just google it.
*straining the yogurt in a colander makes it easy to scoop out once it's done :)
** straining your yogurt will reduce the quantity - when I strained my yogurt overnight, I was left with 1 quart yogurt and 1 quart liquid whey.